In recent years, the economy of Asian countries has grown significantly and is unstoppable. However, the cost to pay for the economic growth is very high. The damage caused by the endless discharge of polluted gas or air has led to declining of national economic growth. For example, the dust haze makes people so afraid and damages their health. Specifically, during the process of production of the refining industry, steel industry, power plants and the semiconductor industry, acidic and alkaline waste-gas will be produced. The acidic waste gas mainly contains sulfur oxides, nitrogen oxides, hydrogen sulfide, sulfur dioxide, nitrogen dioxide, carbon dioxide and so on while the alkaline waste-gas mainly contains gaseous ammonia and gaseous metal oxides produced at high temperature, such as potassium hydroxide, sodium hydroxide and volatile organic waste-gas. Gases such as sulfur dioxide, nitrogen dioxide and suspended particles would irritate the respiratory system of human body and cause discomfort, and high concentrations of such gases can cause heart and respiratory diseases. Carbon monoxide would combine with hemoglobin easily to form carboxyhemoglobin that is hard to decompose, and thus the ability of transporting oxygen is affected.
Currently, the treatment method for acidic and alkaline gas is generally by means of absorption, the principle of which is to absorb pollutants in the waste gas into washing liquid by the gas absorption process with two-phase contact (liquid-gas). The common washing device is a wet scrubber. For a washing device, the waste gas and the washing liquid are required to be in full contact, so as to improve the efficiency of the absorption. On the other hand, for processes of the semiconductor and optoelectronic, the wet scrubber is also mainly used for the treatment of acidic and alkaline gas. The washing device usually contains the packing with a very large surface area, and has the purpose of making gas and liquid to be fully contacted with each other. In practice, the waste gas to be treated flows into the scrubber through its bottom, and the washing liquid is sprayed into the scrubber from its top by a spraying device. After the washing liquid is in contact with the treated waste gas flowing upwardly and absorbs the gaseous solute (pollutants) of the waste gas on the way of the washing liquid flowing through the packing, the washing liquid is converted into a resulting waste liquid, and then the resulting waste liquid is outputted from the bottom of the scrubber.
However, the scrubber mentioned above would cause serious fouling problems. The accumulation of granular particles is mainly due to the precipitation of particulate pollutants carried in the waste gas and the crystallization from the chemical reaction such as the salt crystals formed from acid gas in the waste gas and so on. In addition, the components of the scrubber such as packing, pipelines, nozzles, and flow meters are often attached with the biofilm. If the waste gas contains volatile organic substances, the washing liquid contains too much nitrogen salts (NO3− or NH4+ such as the one in an untreated groundwater), or the waste gas contains nitric acid or ammonia gas, it would provide carbon source for microbial to grow and make the growth of the biofilm more serious. Moreover, in order to prevent the problem of environmental pollution caused by the used waste liquid, it is a common practice in the art to use the used washing liquid again or to reuse the same secondarily (or several times), so as to reduce the total amount of produced waste water. However, it could make concentration of pollutants in above waste liquid increased significantly, resulting in the inconvenience of follow-up process.
Chlorine dioxide is the A1-level safe and efficient physical sterilization deodorant recommended unanimously by World Health Organization and the World Food Organization. By the strong oxidizing ability and effective sterilization of the Chlorine dioxide of the present invention, they prevent scaling deposition and corrosion of pipeline, and strongly oxidize heavy metals and chemical substance. Unlike the reaction mechanism of chlorine gas by the addition or substitution reaction with the reactants, chlorine dioxide is a strong oxidant, composed of one chlorine atom and two oxygen atoms, and combined with 19 electrons. There is an unpaired active free electron in the outermost electron orbital. A special single electron transfer mechanism permits selectivity, and chlorine dioxide attacks the organic molecules (treated object) when the outermost orbital of the organic molecules is full. Chlorine dioxide takes one of the electrons and become chlorite ions and releases oxygen atoms according to the principle of attraction and repulsion, so as to cause irreversible oxidation damage and decomposition. Chlorine dioxide decomposes protein, fat, and nucleic acid of micro-organisms through oxidation, so as to achieve the function of the deactivation, and the principle of which is to oxidize and decompose the amino acid of microorganisms, so as to achieve the deactivation of the diploid of higher animals or plant cells without harmful influence. Therefore, the purpose of disinfection and deodorization is achieved.
It is confirmed by research that chlorine dioxide can effectively destroy organic pollutants in water such as: benzopyrene, anthraquinone, anthracene, chloroform, carbon tetrachloride, phenol, chlorophenol, organic acid, aniline, formaldehyde, amines, thiols, thiourea, nitrophenol and organic sulfide without the occurrence of chlorination reaction. Chlorine dioxide can also oxidize inorganic substances such as iron, lead, manganese, arsenic, sodium, phosphorus, magnesium, calcium, chlorine, nickel, cadmium, chromium, cyanide, sulfide to form non-toxic salts. On the other hand, because the molecules of chlorine dioxide can penetrate the cell wall of bacteria, chlorine dioxide will produce chlorite ions and oxygen after oxidizing cell wall (polysaccharides), and the produced chlorite ions and oxygen would react with the biofilm, resulting that the biofilm begins to peel, which will not lead to drug resistance or the generation of variants of the microbes. Therefore, although chlorine dioxide is effective for removal of biofilm and pollutants. However, there is no device for treating air pollution with chlorine dioxide in the market.
Moreover, when the existing products of chlorine dioxide in the market is mixed with water to form a chlorine dioxide solution in which the water is solvent, because the water still would contain a small amount of heavy metals, microorganisms and ions, chlorine dioxide would react with these heavy metals, microorganisms and ions and so on first, consequently the efficiency of chlorine dioxide for decontamination is significantly reduced. Accordingly, the amount of chlorine dioxide required to achieve the desired effect is greatly increased. Accordingly, in order to improve above problems and effectively apply the chlorine dioxide solution to the air-pollution treatment, the present invention is developed.